1. Field of the Invention
The present invention relates to a navigation system, and more particularly, to a navigation system having a function of branch road guidance based on a running road and a method thereof, for outputting a voice for path guidance based on the running road in case where there is an elevated road or an underpass on a front path at the time of the path guidance.
2. Description of the Related Art
In general, a navigation system refers to a system including a global positioning system (GPS) module (receiver) for receiving each position signal from a plurality of GPS satellites and calculating a self position using the position signal. The navigation system maps the calculated self position to previously stored map data, receives destination information from a user, searches a path from the calculated current self position to a destination, and guides a user to the destination along the searched path.
In general, the navigation system is installed in a vehicle, and performs guidance based on a road. At the time of guidance based on the searched path, the navigation system informs, by voice and graphic, the user of a direction to change when it should change the direction at an intersection. Also, the road generally has divergence points where the branch road such as a surface road, an elevated road, or an underpass diverges from the running road. The navigation system outputs a guide voice based on the branch road to be entered, to guide the branch road along the searched path in the divergence point. For example, when the path is on the elevated road, the navigation system outputs a guide voice such as “Enter elevated road” or “Do not enter elevated road”.
As described above, the conventional navigation system outputs the guide voice based on the branch road. Therefore, when it does not enter the branch road, there is a drawback that the conventional navigation system can cause a driver's confusion.